1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
|
"""Extended file operations available in POSIX.
f = posixfile.open(filename, [mode, [bufsize]])
will create a new posixfile object
f = posixfile.fileopen(fileobject)
will create a posixfile object from a builtin file object
f.file()
will return the original builtin file object
f.dup()
will return a new file object based on a new filedescriptor
f.dup2(fd)
will return a new file object based on the given filedescriptor
f.flags(mode)
will turn on the associated flag (merge)
mode can contain the following characters:
(character representing a flag)
a append only flag
c close on exec flag
n no delay flag
s synchronization flag
(modifiers)
! turn flags 'off' instead of default 'on'
= copy flags 'as is' instead of default 'merge'
? return a string in which the characters represent the flags
that are set
note: - the '!' and '=' modifiers are mutually exclusive.
- the '?' modifier will return the status of the flags after they
have been changed by other characters in the mode string
f.lock(mode [, len [, start [, whence]]])
will (un)lock a region
mode can contain the following characters:
(character representing type of lock)
u unlock
r read lock
w write lock
(modifiers)
| wait until the lock can be granted
? return the first lock conflicting with the requested lock
or 'None' if there is no conflict. The lock returned is in the
format (mode, len, start, whence, pid) where mode is a
character representing the type of lock ('r' or 'w')
note: - the '?' modifier prevents a region from being locked; it is
query only
"""
import warnings
warnings.warn("The posixfile module is deprecated; "
"fcntl.lockf() provides better locking", DeprecationWarning, 2)
class _posixfile_:
"""File wrapper class that provides extra POSIX file routines."""
states = ['open', 'closed']
#
# Internal routines
#
def __repr__(self):
file = self._file_
return "<%s posixfile '%s', mode '%s' at %s>" % \
(self.states[file.closed], file.name, file.mode, \
hex(id(self))[2:])
#
# Initialization routines
#
def open(self, name, mode='r', bufsize=-1):
import __builtin__
return self.fileopen(__builtin__.open(name, mode, bufsize))
def fileopen(self, file):
import types
if repr(type(file)) != "<type 'file'>":
raise TypeError, 'posixfile.fileopen() arg must be file object'
self._file_ = file
# Copy basic file methods
for maybemethod in dir(file):
if not maybemethod.startswith('_'):
attr = getattr(file, maybemethod)
if isinstance(attr, types.BuiltinMethodType):
setattr(self, maybemethod, attr)
return self
#
# New methods
#
def file(self):
return self._file_
def dup(self):
import posix
if not hasattr(posix, 'fdopen'):
raise AttributeError, 'dup() method unavailable'
return posix.fdopen(posix.dup(self._file_.fileno()), self._file_.mode)
def dup2(self, fd):
import posix
if not hasattr(posix, 'fdopen'):
raise AttributeError, 'dup() method unavailable'
posix.dup2(self._file_.fileno(), fd)
return posix.fdopen(fd, self._file_.mode)
def flags(self, *which):
import fcntl, os
if which:
if len(which) > 1:
raise TypeError, 'Too many arguments'
which = which[0]
else: which = '?'
l_flags = 0
if 'n' in which: l_flags = l_flags | os.O_NDELAY
if 'a' in which: l_flags = l_flags | os.O_APPEND
if 's' in which: l_flags = l_flags | os.O_SYNC
file = self._file_
if '=' not in which:
cur_fl = fcntl.fcntl(file.fileno(), fcntl.F_GETFL, 0)
if '!' in which: l_flags = cur_fl & ~ l_flags
else: l_flags = cur_fl | l_flags
l_flags = fcntl.fcntl(file.fileno(), fcntl.F_SETFL, l_flags)
if 'c' in which:
arg = ('!' not in which) # 0 is don't, 1 is do close on exec
l_flags = fcntl.fcntl(file.fileno(), fcntl.F_SETFD, arg)
if '?' in which:
which = '' # Return current flags
l_flags = fcntl.fcntl(file.fileno(), fcntl.F_GETFL, 0)
if os.O_APPEND & l_flags: which = which + 'a'
if fcntl.fcntl(file.fileno(), fcntl.F_GETFD, 0) & 1:
which = which + 'c'
if os.O_NDELAY & l_flags: which = which + 'n'
if os.O_SYNC & l_flags: which = which + 's'
return which
def lock(self, how, *args):
import struct, fcntl
if 'w' in how: l_type = fcntl.F_WRLCK
elif 'r' in how: l_type = fcntl.F_RDLCK
elif 'u' in how: l_type = fcntl.F_UNLCK
else: raise TypeError, 'no type of lock specified'
if '|' in how: cmd = fcntl.F_SETLKW
elif '?' in how: cmd = fcntl.F_GETLK
else: cmd = fcntl.F_SETLK
l_whence = 0
l_start = 0
l_len = 0
if len(args) == 1:
l_len = args[0]
elif len(args) == 2:
l_len, l_start = args
elif len(args) == 3:
l_len, l_start, l_whence = args
elif len(args) > 3:
raise TypeError, 'too many arguments'
# Hack by davem@magnet.com to get locking to go on freebsd;
# additions for AIX by Vladimir.Marangozov@imag.fr
import sys, os
if sys.platform in ('netbsd1',
'openbsd2',
'freebsd2', 'freebsd3', 'freebsd4', 'freebsd5',
'freebsd6', 'freebsd7', 'freebsd8',
'bsdos2', 'bsdos3', 'bsdos4'):
flock = struct.pack('lxxxxlxxxxlhh', \
l_start, l_len, os.getpid(), l_type, l_whence)
elif sys.platform in ('aix3', 'aix4'):
flock = struct.pack('hhlllii', \
l_type, l_whence, l_start, l_len, 0, 0, 0)
else:
flock = struct.pack('hhllhh', \
l_type, l_whence, l_start, l_len, 0, 0)
flock = fcntl.fcntl(self._file_.fileno(), cmd, flock)
if '?' in how:
if sys.platform in ('netbsd1',
'openbsd2',
'freebsd2', 'freebsd3', 'freebsd4', 'freebsd5',
'bsdos2', 'bsdos3', 'bsdos4'):
l_start, l_len, l_pid, l_type, l_whence = \
struct.unpack('lxxxxlxxxxlhh', flock)
elif sys.platform in ('aix3', 'aix4'):
l_type, l_whence, l_start, l_len, l_sysid, l_pid, l_vfs = \
struct.unpack('hhlllii', flock)
elif sys.platform == "linux2":
l_type, l_whence, l_start, l_len, l_pid, l_sysid = \
struct.unpack('hhllhh', flock)
else:
l_type, l_whence, l_start, l_len, l_sysid, l_pid = \
struct.unpack('hhllhh', flock)
if l_type != fcntl.F_UNLCK:
if l_type == fcntl.F_RDLCK:
return 'r', l_len, l_start, l_whence, l_pid
else:
return 'w', l_len, l_start, l_whence, l_pid
def open(name, mode='r', bufsize=-1):
"""Public routine to open a file as a posixfile object."""
return _posixfile_().open(name, mode, bufsize)
def fileopen(file):
"""Public routine to get a posixfile object from a Python file object."""
return _posixfile_().fileopen(file)
#
# Constants
#
SEEK_SET = 0
SEEK_CUR = 1
SEEK_END = 2
#
# End of posixfile.py
#
|
